A novel FTA™ elute card collection method that improves direct DNA amplification from bloodstained concrete.

Concrete is a common construction material found in residential and commercial buildings, bridges and parking lots that is a composite matrix containing aggregate held together with cement. The porous nature of concrete can make the collection and genotyping of biological fluids, such as blood, challenging. Forensic evidence can become embedded within the matrix, potentially reducing the amount of DNA available for analysis. In forensic science, "direct" amplification refers to a genotyping method that amplifies a DNA profile directly from a sample without DNA extraction, saving time and money. We investigated a novel application of Whatman™ FTA™ Elute cards in their ability to directly amplify PowerPlex® Fusion and Y23 profiles from minute amounts of blood that had been deposited on different concrete structures. In comparison to traditional collection methods, directly profiling blood stained construction materials using FTA™ Elute cards increased the percentage loci amplified and significantly improved both allele peak height and peak height ratio while reducing allelic drop-out. FTA™ Elute cards can provide a reliable, inexpensive and superior alternative to traditional methods.

A potential new diagnostic tool to aid DNA analysis from heat compromised bone using colorimetry: A preliminary study.

Extracting viable DNA from many forensic sample types can be very challenging, as environmental conditions may be far from optimal with regard to DNA preservation. Consequently, skeletal tissue can often be an invaluable source of DNA. The bone matrix provides a hardened material that encapsulates DNA, acting as a barrier to environmental insults that would otherwise be detrimental to its integrity. However, like all forensic samples, DNA in bone can still become degraded in extreme conditions, such as intense heat. Extracting DNA from bone can be laborious and time-consuming. Thus, a lot of time and money can be wasted processing samples that do not ultimately yield viable DNA. We describe the use of colorimetry as a novel diagnostic tool that can assist DNA analysis from heat-treated bone. This study focuses on characterizing changes in the material and physical properties of heated bone, and their correlation with digitally measured color variation. The results demonstrate that the color of bone, which serves as an indicator of the chemical processes that have occurred, can be correlated with the success or failure of subsequent DNA amplification.